The present invention relates in general to deck mounted automobile type speakers for stereo sound reproducing systems and the like, and more particularly to two-way stereo speaker structures for automobile rear decks and the like capable of providing tweeter and midrange sound reproducers and mounting structure conveniently adaptable to mounting such speakers on the decks of such automobiles and the like.
Conventional electrodynamic speakers customarily comprise a cone of semi-rigid material which is secured at its outer edge to a rigid frame. In many instances, the cone is corrugated near the outer edge to provide a degree of flexibility in this region of the cone so as to permit the cone to move as a piston under the influence of a voice coil which is secured to the cone at its apex. The voice coil is located within a cylindrical gap of a magnet which provides a substantially constant magnetic field across the gap. The magnetic field set up by the audio frequency currents supplied to the voice coil interacts with the constant field of the magnet with the result that physical forces are applied to the voice coil which tend to move the voice coil and the attached cone in a direction parallel to the axis of the cone.
It is normal in the mounting structure of conventional deck mounted speakers to provide a set of four threaded bushings fixed in the grille of such speaker units, for example by molding them in the grille or installing them by sonic welding techniques, to receive end portions of threaded mounting studs which extend through mounting holes in the automobile rear deck adjacent the hole provided for the speaker. After the threaded studs are threaded into the bushings fixed in the grille, the grille is positioned over the speaker hole in the deck and the threaded mounting studs extended downwardly through the mounting stud holes in the deck and the holes in mounting formations on the speaker basket to secure the basket or main ring portion of the speaker by the mounting studs and nuts applied thereon onto the deck to mount the basket or mounting frame, the cone, the centering spider, the voice coil support and the voice coil, as a unit, on the stationary rear deck.
The necessity of providing the separate bushings in the grille in some manner, to receive the threaded mounted studs, has been a source of problems and introduces a cost factor which it would be desirable to reduce in some manner. Usually the threaded bushings are inserted into the grille as a post-operation after molding of the grille. To assure that the threaded bushings hold in the plastic material of the grille, the bushing is usually pushed in using "sonic" welding. The bushings have to be placed in the grille one at a time, which is costly. Another conventional method of placing such bushings in the grille is to load a mold for four bushings and then mold the plastic grille around the bushings. This causes problems because the bushings are not firmly held in the mold during the molding process and can fall out of position and damage the mold.
An object of the present invention is the provision of a novel speaker mounting system to facilitate mounting of the speaker by fasteners depending from the grille through the deck and through holes in the speaker basket to receive threaded mounting nuts, which reduces the cost associated with deck mounting systems wherein threaded bushings must be incorporated in the grille.
Another object of the present invention is the provision of a novel speaker mounting system including a speaker grille to be supported over a hole in a horizontal deck, wherein threaded mounting studs are threaded into unthreaded holes molded in the plastic grille and flat spring nuts are applied onto the studs to positions abutting the grille, or preformed thin shoulders are provided on the mounting studs, to bear against the top surface of the deck when installed and support the weight of the speaker to be carried by the mounting studs underneath the deck.
Other objects, advantages and capabilities of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings illustrating an embodiment of the invention incorporating my novel thin speaker design, although it will be understood that the mounting system of the present invention is equally applicable to conventional deep speakers.